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harlow

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RGB Monitor setup

System: Generic PC, Linux RedHat 7.1 (kernel 2.4.2-2), XFree86 4.0

Video: ATI MACH 64 4 mb

Monitor: Sony/Sun GDM-1962b.  Using a Sun-supplied cable adaptor

Problem: Overscan, dim

I managed to install an ex-Sun monitor and get it working on my Linux box by following numerous hints and emails found on various web sites.

Now I am in the "tuning" phase and wonder if anyone can help.  The XF86 server selects an 1152x864 24 bit mode that seems to be pretty good, but the raster is a little too wide for the physical screen.  There are no external controls on the monitor to reduce the raster size; are there internal controls or hidden commands that can do this?

The other problem is that the raster is quite dim compared to the way it looked on the Sun system.  The brighness and contrast controls are already at max, but it is hard to see, even with room lights dimmed.  I suspect that this has to do with the voltage levels on the RGB lines or something; is there any way to compensate or tune this to make the raster brighter?

Thanks

JEH

PS: If there is a better group to post this question to, please advise.
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ahoffmann
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AFAIK the GDM-1962 is fixed-frequency monitor.
I managed to run a GDM-1932 (an amcestor?) with XFree, but have simmilar problems:
  must use full brightness
  displayed area is smaller than max screen size

I'm still using XFree 3.x, probably 4.x can manage it more accurate.
I used xvidtune to find usefull settings.
I also use a resolution of 1024x768.
Also remember that these monitors usually use a resolution of 11xx x 900 (ugly), but I didn't find any values to get it running in this resolution.
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harlow

ASKER

It is advertised as being fixed frequency, but XFree probes it and says it can do 70-85 Hz vertical and 61.6-80 KHz horizontal.  I have set it up with this modeline:

modeline "1152x864" 100.0 1152 1156 1196 1392 864 865 868 892 +hsync +vsync Composite

It works pretty well except for the overscan and dimness. I have fiddled with it under xvidtune and can improve it a little bit, but it loses sync if I get much away from these numbers.  I went through the HOWTO and concocted a 1024x768 and a 1280x1024 modeline that should have worked, but they didn't.

Guess I'm stuck with it, but it is not really that bad.  Still interested to know if anyone familiar with this monitor can tell me whether there are hidden controls somewhere for tweaking the raster width and the brightness.

JEH
even a fixed frequency monitor can be driven with a small range of horizozal and vertical frequences.
XFree's auto-probing just recognices this  'cause it cannot detect fixed frequency.
The only way I know is to fiddle arround with the modline.

XFree usually comes with a huge monitor database, for example in /usr/doc/packages/xf86/Monitors (also xheck in /usr/X11).
harlow:
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ahoffmann
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